A simplified technique for fabricating complete dentures for patients with Parkinson's disease: a case report / Técnica simplificada como alternativa para confecção de próteses totais para paciente com Doença de Parkinson: relato de caso

BACKGROUND AND OBJECTIVE: Parkinson's disease is a neurological disorder that affects 1% of individuals aged 60 years and older. The associated symptoms can impose limitations on the available dental treatment options. CASE DESCRIPTION: This case report follows the CARE guidelines and presents an adapted and simplified technique to fabricate complete dentures for a 74-year-old male edentulous patient with Parkinson's disease. This modified technique enabled the fabrication of complete dentures in 4 clinical sessions of approximately 40 minutes. The first session involved manufacturing a preliminary impression with fast-setting alginate. The base plates and occlusal rims were then adjusted for artificial teeth arrangement during the second session. The final prosthesis was completed in the third session, which involved a teeth try-in and fabrication of a functional impression with low-melting thermoplastic material and polyether. Finally, denture installation was performed in the fourth session and follow-up consisted of 3 weekly sessions. DISCUSSION: Considering that the treatment provided satisfactory aesthetics and function, mastication and socialization benefits, and improved the self-esteem and well-being of the older patient with Parkinson's disease, the authors suggest this adapted and simplified technique for fabricating complete dentures. (AU)

JUSTIFICATIVA E OBJETIVO: A doença de Parkinson é uma desordem neurológica que afeta 1% dos indivíduos com 60 anos ou mais. Os sintomas associados podem impor limitações nas opções de tratamento odontológico disponíveis. DESCRIÇÃO DO CASO: Este relato de caso segue o protocolo CARE e apresenta uma adaptação da técnica simplificada para confecção de novas próteses totais, para um paciente edêntulo, do sexo masculino, de 74 anos com doença de Parkinson. Essa técnica modificada possibilita a confecção de próteses totais em quatro sessões clínicas de aproximadamente 40 minutos. A primeira sessão envolveu uma moldagem preliminar com alginato de presa rápida. As placas articulares com rodetes de cera foram ajustadas para montagem dos dentes artificiais durante a segunda sessão. A prótese definitiva foi concluída na terceira sessão, que envolveu a prova dos dentes e moldagem funcional com material termoplástico de baixa fusão e poliéter. Por fim, a instalação da prótese foi realizada na quarta sessão e o acompanhamento consistiu em três sessões semanais. DISCUSSÃO: Considerando que o tratamento proporcionou estética e função satisfatórias, benefícios mastigatórios e de socialização, melhora da autoestima e bem-estar do idoso com doença de Parkinson, os autores sugerem o uso da adaptação da técnica simplificada para confecção de prótese total. (AU)

Prosthetic complications and quality of life among wearers of mandibular overdenture with the Facility-Equator system

Abstract This longitudinal study aimed to assess the performance of the Facility-Equator system as mandibular overdenture (MO) retainers from a prosthetic perspective during 2 years of loading and to investigate the oral health-related quality of life (OHRQoL) and whether prosthetic events can affect the OHRQoL. Twenty-four patients (68.1 ± 7.51 years) reported their OHRQoL through the Geriatric Oral Health Assessment Index (GOHAI) and Oral Health Impact Profile (OHIP-EDENT) questionnaires before MO loading and after 1 and 2 years of usage. Prosthetic occurrences were recorded during this period. Data were analyzed using the Wilcoxon test, Mann-Whitney test, and Spearman correlation coefficients. Of the 127 prosthetic events that occurred in the first year, the most frequent events were prosthesis adjustments (16.5%), dislodgement of the Equator attachment (14.17%), and O-ring replacement (11.8%). Eighty-seven prosthetic events were recorded in the second year, the most frequent events being prosthesis adjustments (27.6%), O-ring replacement (20.7%), and recapturing the female matrix (11.5%). All domains of the GOHAI and OHIP-EDENT questionnaires exhibited a significant difference (p < 0.05) between the baseline and 1- and 2-year evaluations, except in the Social Disability and Psychological Discomfort domains (p > 0.05) of OHIP-EDENT after 1 year. Complications related to prosthetic maintenance, such as fracturing of the prosthesis, Equator dislodgement, prosthesis rebasing, and new overdenture confection, affect the OHRQoL (p < 0.05), primarily the Physical Pain and Discomfort domains, especially in the first year of MO loading.

Influence of abutment collar height and implant length on stress distribution in single crowns

Abstract This in silico study evaluated the influence of the abutment collar height and implants length on the biomechanical behavior of morse taper single dental implants with different crown-to-implant ratio. Six virtual models were constructed (S11, M11, L11, S13, M13 and L13) by combining short (S: 2.5 mm), medium (M: 3.5 mm) or long (L: 4.5 mm) abutment collar heights with different implant lengths (11 or 13-mm). An upper central incisor of 11-mm height was constructed on top of each abutment. Each set was positioned in a virtual bone model and exported to analyze mathematically. A 0.60-mm mesh was created after convergence analysis and a 49 N load was applied to the cingulum of the crown at an angle of 45°. Load-generated stress distribution was analyzed in the prosthetic components according to von Mises stress criteria (σvM) and in the cortical and cancellous bone by means of shear stress (εmax). The use of longer collar abutments (L11) increased the stress on the abutment by 250% and resulted in 40% higher stresses on the screw and 92% higher cortical shear stresses compared to short collared abutments (S11). Increasing the implant length produced a slight stress reduction on cortical bone. Cancellous bone was not affected by the crown-to-implant ratio. Longer abutment collars concentrate stresses at the implant level and cortical bone by increasing the crown-to-implant ratio.

Resumo Este estudo avaliou a influência da altura da porção transmucosa do pilar protético com junção cone morse e do comprimento dos implantes no comportamento biomecânico coroas unitárias com diferentes proporção coroa-implante. Seis modelos virtuais (S11, M11, L11, S13, M13 e L13) foram construídos combinando pilares protéticos com transmucoso considerado: curto (S: 2,5 mm), médio (M: 3,5 mm) ou longo (L: 4,5 mm) com diferentes comprimentos de implantes (11 ou 13 mm). Um incisivo central superior de 11 mm de altura foi construído para cada pilar. Cada conjunto foi posicionado em um modelo de osso virtual e exportado para análise matemática. Uma malha de 0,60 mm foi criada após análise de convergência e uma carga de 49 N foi aplicada ao cíngulo da coroa em um ângulo de 45°. A distribuição de estresse gerada por carga foi analisada nos componentes protéticos de acordo com o critério de tensão de von Mises (σvM) e no osso cortical e medular por meio da tensão de cisalhamento (εmax). O uso de pilares com porção transmucosa mais longa (L11) aumentou a tensão no pilar protético em 250%, e resultou em tensões 40% maiores no parafuso e 92% no osso cortical em relação aos pilares com transmucoso curto (S11). O aumento do comprimento do implante produziu uma ligeira redução da tensão de cisalhamento no osso cortical. O osso medular não foi afetado pela relação coroa-implante. Pilares protéticos com porção transmucosa mais longa concentram tensões no implante e no osso cortical, quando a proporção coroa-implante é aumentada.

Prevalence of risk factors for denture stomatitis in complete denture wearers

Aim: The prevalence of denture stomatitis and the relationship with its risk factors was evaluated via secondary data from 62 complete denture (CD) wearers, between 2015 and 2017. Methods: The data was stored in an Excel database and was analyzed using the statistics software STATA/SE 12.0. A descriptive analysis was performed taking into account a categorization of the clinical variables according to risk factor in 4 domains: CD usage, systemic health, hygiene habits, and usage habits. The association amongst the denture stomatitis and risk factors variables was tested by the Chi-square test and the results were statistically significant at p-values <0.05. Results: The CD wearers participants were composed by a majority of elderly (80.64%) and women (72.78%); with 45.16% having been using the current denture for more than 10 years and another 74.19% related a continuous usage. Diabetes and hypertension were related by 83.87% and 67.74%, respectively, with 87.10% using medication. Although 75.80% reported cleaning their dentures 3 times per day or more, and 59.68% considered their oral hygiene very good, 50% of the complete dentures showed dirtiness and clinical signs of Denture Stomatitis were present in 30.64% of the patients. Despite of the evaluated sample shows many risk factors for the development of the disease, an association between the variables was not observed. Conclusion: Considering the high prevalence of the disease in the studied sample, preventive and educational measures on denture usage and hygiene must be reinforced in order to maintain the oral health of the edentulous patients

Simplified micrometric surface characterization of different implant surfaces available on the Brazilian market

Aim: This study characterized the implant surfaces available on the Brazilian market in terms of topography, chemical composition, and roughness. Methods: The following brands were selected according to their surfaces: Kopp (Ko), Signo Vinces (Sv), Neodent (Ne), Osseotite (Os) NanoTite (Nt), SIN (Si), Titanium Fix (Tf), conventional Straumann (Str), Active SLA (SLA). The morphological analysis and the alloy impurities and implant surface contaminants were analyzed by SEM-EDS. Surface roughness parameters and 3-D reconstructions were obtained by laser microscopy (20x). Two distinct areas were evaluated: i) the cervical portion (no surface treatment), and ii) the middle third (treated surface). Results: The characterization of the implant surfaces by SEM showed morphological differences between the thread geometries and surface morphology at 800x and 2000x magnification. The EDS elemental analysis showed a predominance of titanium (Ti) for all implants. The SLA surface showed only peaks of Ti while other implants brands showed traces of impurities and contaminants including Al, C, PR, F, Mg, Na, Ni, O, P, and SR. The implant surface roughness in the cervical portion did not exceed Ra 0.5­1.0 µm, constituting a minimally rough surface and obtaining acceptable standards for this region. Only Nt, Str, and SLA presented Ra above 2 µm in the middle third area showing a rough surface favorable for osseointegration. Conclusion: This study concluded that there is no established standard for morphology, chemical composition and implant surface roughness that allows a safe comparison between the available dental implant surfaces. National implant brands generally contain more impurities and surface contaminants than their international counterparts and were consequently more sensitive to the surface treatment techniques

Exploratory and confirmatory factorial analysis of the OHIP-Edent instrument

Abstract Several instruments have been used to measure oral health-related quality of life (OHRQoL). The Oral Health Impact Profile (OHIP) questionnaire was based on the concept that sequential events related to oral diseases can cause discomfort, functional limitations and consequently, result in dysfunctions and even disabilities. There are few studies in the literature that structurally analyze the instruments to verify whether they measure the requirements to which they were designed to. The objective of the study was to evaluate the internal structure of the OHIP-Edent questionnaire. The OHIP-Edent was administered to 54 edentulous patients' wearers of conventional complete dentures. For structural analysis, an exploratory factorial analysis (EFA) was carried out. After determining the internal consistency of the model (Cronbach's alpha = 0.88), the fit was checked using the root mean square error approach (value 0.04), the comparative fit index (value 0.982) and the Tucker-Lewis index (value 0.976). After analysis of the 19 questions and the seven domains proposed in the OHIP-Edent questionnaire, the hypothetical factorial model showed three dimensions denominated "Physical Impact", "Psychological Impact" and "Social Impact". In this sample of conventional complete denture wearers, the OHIP-Edent seems adequate to measure the "Physical Impact", "Psychological Impact", and "Social Impact" of the OHRQoL. The confirmatory factorial analysis confirmed the model and, through adjustment indexes, it was verified that the three dimensions have convergence and consistence adequate in order to characterize the OHRQoL construct with validity.

Can implant surfaces affect implant stability during osseointegration? A randomized clinical trial

Abstract This randomized clinical trial evaluated the insertion torque (IT), primary, and secondary stability of dental implants with different surface treatments during the osseointegration period. Nineteen patients with bilateral partial edentulism in the posterior mandibular region were randomly allocated to two implant brand groups and received implants with different surface treatments in the opposite site of the arch: Osseotite and Nanotite or SLA and SLActive. During implant placement, the maximum IT was recorded using a surgical motor equipped with a graphical user interface. The implant stability quotient (ISQ) was assessed immediately after the IT, and was measured weekly via resonance frequency analysis during 3 months. The data were analyzed by a one-way ANOVA, the Bonferroni test, paired t tests and Pearson's correlation coefficient. The IT values were similar (p > 0.05) for all implant types ranging from 43.82 ± 6.50 to 46.84 ± 5.06. All implant types behaved similarly until the 28th day (p > 0.05). Between 35 and 56 days, Osseotite and SLActive showed lower ISQ values (p < 0.001) compared to Nanotite and SLA implants. After 56 days, only Osseotite maintained significantly lower ISQ values than the other implants (p < 0.05). After 91 days the ISQ values were significantly higher than the baseline for all four implant types (p < 0.001). The ISQ and IT values were significantly correlated at the baseline and at the final evaluation for Osseotite, Nanotite, and SLActive implants (p < 0.001). After 91 days, ISQ and IT values were only significantly correlated for the Osseotite implants (p < 0.05). All implants types exhibited acceptable primary and secondary stability.

Short-term quality of life change perceived by patients after transition to mandibular overdentures

Abstract The aim of this longitudinal observational study was to evaluate the oral health-related quality of life (OHRQoL) following patient rehabilitation with implant-retained mandibular overdentures (IMO) and to identify the contribution of the different domains to OHRQoL. The Oral Health Impact Profile (OHIP-EDENT), Dental Impact on Daily Living (DIDL), and Geriatric Oral Health Assessment Index (GOHAI) questionnaires were completed twice by 25 patients: after 3 months of rehabilitation with complete dentures (CD) and after 3 months of IMO loading using stud abutments. The evaluation after IMO rehabilitation showed significant improvement in three DIDL domains: appearance (p = 0.011), eating and chewing (p = 0.003), and general performance (p = 0.003). The GOHAI results showed significant differences in two domains: psychosocial (p = 0.005) and pain and discomfort (p = 0.0004). The OHIP-EDENT outcomes showed significant improvements in five domains: functional limitation (p = 0.0001), physical pain (p = 0.0002), physical disability (p = 0.0010), and psychological disability and handicap (p = 0.032). The largest observed effect sizes were close to one standard deviation and were observed in the eating and chewing domain (0.93) of the DIDL; the pain and discomfort domain (0.83) of the GOHAI, and the functional limitation (0.89), physical pain (1.02), physical disability (0.84) domains of the OHIP-EDENT. The percentage of satisfied patients increased in all domains. Self-reported OHRQoL of CD wearers was significantly improved after 3 months of treatment with IMO, especially concerning the functional and pain-related aspects.

Implantes, componentes e os honorários profissionais: o que agrega mais no custo final da Implantodontia? Análise de custos entre seis marcas comercialmente disponíveis no Brasil / Dental implants, components, and professional fees: what is most signifi cant factor in the overall cost of Brazilian implant dentistry? A cost analysis among six different commercially available brands

Objetivo: sistematizar e organizar o conjunto de informações relacionadas ao planejamento e manejo de custos na área de Implantodontia. Material e métodos: uma reabilitação mandibular (prótese total implantorretida com carregamento imediato e ancorada por cinco implantes) foi utilizada como referência para custos. Para determinação do valor total, foram somados os honorários e os custos do profissional com o consultório, com componentes cirúrgicos e protéticos para execução do caso, além dos custos laboratoriais. O custo total foi acrescido em 20% devido à taxa de risco do tratamento. Seis marcas comerciais foram selecionadas para realização dos orçamentos. Os valores de todos os componentes em moda corrente (Reais) foram expostos baseados em um denominador comum (X). Ainda, as porcentagens de custo de cada componente segundo o tipo de cilindro selecionado também foram descritas. Resultados: o valor do tratamento conforme o sistema de implantes variou entre 64,4 X e 209,6 X. No custo fi nal, a variação ficou entre 243,1 X e 441,4 X. Conclusão: embora este trabalho não tenha englobado no custo as sessões de retorno para acompanhamento e higienização, fratura de pilares protéticos e parafusos, perda de implantes e a fratura de dentes artificiais, a maior variação nos valores do tratamento refere-se aos sistemas de implantes selecionados. Entretanto, o uso de cilindros calcináveis ou de cilindros com base metálica não interferiu significativamente no custo total, o que favorece a postura clínica de utilizar componentes com partes pré-fabricadas para aliviar os problemas biológicos na interface implante/prótese.

Objective: to organize the information related to treatment and cost management for Implant Dentistry. Material and methods: a mandibular restoration (a five implant-retained prosthesis under immediate loading) was used as reference for cost analysis. To determine the overall value, professional, surgical, prosthetic component, and laboratory costs were added. The overall cost was increased in 20% due to the treatment risk. Six different commercial manufacturers were selected to present the costs. The values in the real currency (BRL) were converted to a common denominator (X). Also, the cost percentages associated to each prosthetic cylinder were also described. Results: the overall treatment value according to each implant system ranged from 64.4 X to 209.6 X. For the overall cost, the variation was between 243.1 and 44.1 X. Conclusion: although recall sessions have not been included in this paper (e.g. hygiene maintenance, abutment screw fracture/ loosening, implant loss, and artifi cial tooth fracture events), the great cost variation relates to the choice of the dental implant system. However, the use of pre-fabricated or plastic burnout cylinders did not signifi cantly interfere in the overall cost, which favors the use of pre-fabricated parts to alleviate the biological issues at the implant-prosthesis interface.

Mechanical behavior of NiCr and NiCrTi alloys for implant prosthetic components / Comportamento Mecânico de ligas NiCr e NiCrTi utilizados para componentes protéticos de implantes

Objective: The aim of this study was to evaluate the tensile and hardness mechanical properties, as well as the composition and microstructure of three different alloys used for implant prosthestic components casting. Methods: The alloys were divided into three groups: Tilite (Tilite), Vera (Verabond) and Malloy (DanCeramalloy). For the tensile test, the specimens (n = 10) of each group were evaluated in “alter” form and the maximum load fracture, the deformation at maximum load and Young´s modulus were determined. The data was subjected to one-way ANOVA and Turkey’s test. For the hardness test, five discs from each group were evaluated for Vickers hardness. The data was analyzed using multiple regression ANOVA followed by the Turkey’s test. The significance level was set at 5% (α = 0.05). The composition and microstructure was determined through analysis of two specimens from each group by metallographic analysis (MEV/EED). Results: With regards to maximum load tensile, the deformation and the Young´s Modulus the three alloys evaluated were statistically similar. Regarding hardness, Tilite showed significant higher values than the others alloys. Conclusion: All the examined alloys can be used in implant prosthetic components and the presence of the element Ti did not influence the mechanical behavior of the alloy

Objetivo: O objetivo deste estudo foi avaliar as propriedades mecânicas de tensão e dureza, assim com a composição e microestrutura de três diferentes ligas utilizadas em componentes protéticos de implantes. Métodos: As ligas foram divididas em três grupos: Tilite (Tilite), Vera (Verabond) e Malloy (DanCeramalloy). Para o teste de tensão, os espécimes (n = 10) de cada grupo foram avaliados em forma modificada e a força máxima de fratura, a deformação em carga máxima e o módulo de Young foram determinados. Os dados foram submetidos ao teste ANOVA a um fator e teste de Tukey. Cinco discos de cada grupo foram avaliados para o teste de dureza Vickers. Os dados foram analisados utilizando o teste ANOVA de regressão múltipla, seguido do teste de Tukey. O nível de significância adotado foi de 5% (α = 0,05). A composição e microestrutura foram determinados em dois espécimes de cada grupo por meio de análise metalográfica (MEV/EED). Resultados: Não houve diferenças estatísticas entre as três ligas estudadas em relação à força de tensão máxima, à deformação e ao modulo Young. Em relação à dureza, Tilite mostrou valores estatisticamente superiores em comparação às outras ligas. Conclusão: Todas as ligas examinadas podem ser utilizados em componentes protéticos de implantes e a presença do elemento Titânio não influenciou o comportamento das ligas.

Poly (Methyl Methacrylate) absorption and releasing of nystatin and fluconazole / Absorção e liberação de nistatina e fluconazol por polimetilmetacrilato

Objectives: The aim of this study was to verify if there are poly (methyl methacrylate) (PMMA) absorptionand releasing of nystatin (NYS) and fluconazole (FLZ) after simulated treatment of oral candidosis. Materialsand methods: Specimens (30 × 25 × 5 mm) prepared with PMMA polymerized by hot water bath or microwaveenergy were immersed into NYS (3.12 μg/mL), FLZ (2.56 μg/mL) or deionized water (control) during14 days at 35 ± 2 °C. After treatment simulation, specimens were immersed into distilled water during 3, 7, 10and 14 days. The immersion liquid was changed after each analysis. Higher performance liquid chromatographywas used in order to detect antifungal compounds. In order to determine if there was surface depositionof drugs on PMMA resin, specimens were analyzed with electronic microscopy (SEM). Results: None of theantifungal agents was released from the PMMA resins. Conclusion: Within the limitations of this study, itcould be concluded that PMMA resins had no drug absorption with posterior release.

Objetivos: O objetivo deste estudo foi verificar se o poli (metil metacrilato) (PMMA) é capaz de absorver e liberar nistatina (NYS) e fluconazol (FLZ) após simular um tratamento para candidose oral. Materiais e métodos:Espécimes (30 × 25 × 5 mm) foram preparados em resina de PMMA por banho de água quente ou energia demicro-ondas e, em seguida, imersos em solução contendo NYS (3.12 μg/mL), FLZ (2.56 μg/mL) ou água deionizada(controle) durante 14 dias a 35 ± 2 °C. Após a simulação de tratamento, os espécimes foram imersos em água destilada durante 3, 7, 10 e 14 dias. O líquido de imersão foi trocado após cada análise. Cromatografia líquida de alta performance foi utilizada para detectar a presença dos agentes antifúngicos. Para determinar se houve deposição dos agentes antifúngicos na superfície de PMMA, os espécimes foram analisados por microscopia eletrônica de varredura(MEV). Resultados: Não houve liberação de agentes antifúngicos dos espécimes. Conclusão: Considerando as limitações deste estudo, pode-se concluir que a resina de PMMA não absorve ou libera agentes antifúngicos.

Chewing side, bite force symmetry, and occlusal contact area of subjects with different facial vertical patterns

Craniofacial dimensions influence oral functions; however, it is not known whether they are associated with function asymmetry. The objective of this study was to evaluate chewing side preference and lateral asymmetry of occlusal contact area and bite force of individuals with different craniofacial patterns. Seventy-eight dentate subjects were divided into 3 groups according to the VERT index as follows: (1) mesofacial, (2) brachyfacial and (3) dolichofacial. Chewing side preference was evaluated using jaw tracking equipment, occlusal contact area was measured by silicon registration of posterior teeth, and bite force was measured unilaterally on molar regions using 2.25 mm-thick sensors. Statistical analysis was performed using ANOVA on Ranks, Student's t-test, and Mann-Whitney tests at a 5 percent significance level. Mesofacial, brachyfacial, and dolichofacial subjects presented more occlusal contact area on the left side. Only dolichofacial subjects showed lateral asymmetry for bite force, presenting higher force on the left side. No statistically significant differences were found for chewing side preference among all groups. Within the limitations of this study, it can be concluded that craniofacial dimensions play a role in asymmetry of bite force. ClinicalTrials.gov ID: NCT01286363.

Occlusal force, electromyographic activity of masticatory muscles and mandibular flexure of subjects with different facial types

OBJECTIVE: The aim of this study was to evaluate whether vertical facial patterns influence maximal occlusal force (MOF), masticatory muscle electromyographic (EMG) activity, and medial mandibular flexure (MMF). MATERIAL AND METHODS: Seventy-eight dentate subjects were divided into 3 groups by Ricketts's analysis: brachyfacial, mesofacial and dolychofacial. Maximum occlusal force in the molar region was bilaterally measured with a force transducer. The electromyographic activities of the masseter and anterior temporal muscles were recorded during maximal voluntary clenching. Medial mandibular flexure was calculated by subtracting the intermolar distance of maximum opening or protrusion from the distance in the rest position. The data were analyzed using ANOVA followed by Tukey's HSD test. The significance level was set at 5 percent. RESULTS: Data on maximum occlusal force showed that shorter faces had higher occlusal forces (P<0.0001). Brachyfacial subjects presented higher levels of masseter electromyographic activity and medial mandibular flexure, followed by the mesofacial and dolychofacial groups. Additionally, dolychofacial subjects showed significantly lower electromyographic temporalis activities (P<0.05). CONCLUSION: Within the limitations of the study, it may be concluded that maximum occlusal force, masticatory muscle activity and medial mandibular flexure were influenced by the vertical facial pattern.

Microstructural characterization of Ni-Cr-Mo-Ti and Ti-6Al-4V alloys used in prosthetic abutments / Caracterização microestrutural das ligas Ni-Cr-Mo-Ti e Ti-6Al-4V utilizadas para pilares de próteses

Purpose: Titanium alloys are commonly used for prosthetic abutments fabrication, but these alloys present high cost and difficult handling. Alternative Ni-Cr alloys with Mo and Ti combination have been proposed. This study compared the alloys Ti-6Al-4V and Ni-Cr-Ti-Mo by analyzing their surface properties such as hardness, morphology and microstructural characterization. Methods: Five discs (5 x 2 mm) of commercially Ti-6Al-4V and Ni-Cr-Ti-Mo alloys were used to evaluate Vickers hardness by hardness micro indentation test. The same specimens were analyzed by scanning electron microscopy (SEM) regarding surface morphology and subjected to a metallographic analysis of the microstructure by optical microscopy. Data on surface hardness were analyzed using one-way ANOVA followed by Tukey test (α = 0.05). Results: The Ni-Cr-Mo-Ti alloy showed significantly higher Vickers hardness (kg/mm2) values (452.2 ± 3.9) than the Ti-6Al-4V alloy (375.7 ± 15.2). The surface morphology evaluated by SEM revealed differences between the alloys. Metallographic analyses, for both alloys, showed a two-phase equilibrium microstructure, with the presence of e α + ß phase for Ti-6Al-4V; and gamma (γ) primary phase and gamma-prime (γ´) as a second phase for Ni-Cr-Mo-Ti. Conclusion: It can be concluded that both alloys present the requirements to be used in prosthetic abutments.

Objetivo: As ligas de titânio são comumente usadas para a fabricação de componentes protéticos, entretanto apresentam alto custo e dificuldade de manuseio laboratorial. Ligas alternativas a base de Ni-Cr combinadas com Mo e Ti também tem sido propostas com o mesmo objeto. Este estudo comparou as ligas Ti-6Al-4V e Ni-Cr-Ti-Mo pela análise de suas propriedades de superfície como dureza, morfologia e caracterização da microestrutura.Metodologia: Cinco discos (5 × 2 mm) das ligas Ti-6Al-4V e Ni-Cr-Ti-Mo foram utilizados para a avaliação da dureza Vickers, análise de morfologia de superfície por meio da microscopia eletrônica de varredura (MEV) e análise da microestrutura pela análise metalográfica. Os dados da dureza de superfície foram analisados pela Análise de Variância a um nível seguida do teste de Tukey (α = 0,05). Resultados: A liga Ni-Cr-Mo-Ti apresentou os maiores valores de dureza Vickers (kg/mm2) (452,2 ± 3,9) comparada a liga Ti-6Al-4V (375,7 ± 15,2) A morfologia de superfície avaliada por MEV revelou características distintas entre as ligas. A análise metalográfica para ambas as ligas mostrou uma microestrutura com equilíbrio de duas fases, com a presença de fase α + ß para Ti-6Al-4V; e fase gamma primária (γ) e fase gamma-prime (γ') como secundária para Ni-Cr-Mo-Ti. Conclusão: Ambas as ligas podem ser utilizadas para fabricação de pilares protéticos.

Prevalência de sinais e sintomas de desordens temporomandibulares esuas associações em jovens universitários / Prevalence of signs and symptoms of temporomandibular disorders and their association with young university students

Objetivo: Verificar a prevalência de sinais e sintomas de desordem temporomandibular e sua associação com ruídos articulares, hipermobilidade articular, interferências oclusais, tratamento ortodôntico e bruxismo em uma população específica, composta por jovens universitários. Métodos: Foram selecionados 117 voluntários (média de 22 anos de idade) do curso de graduação em Odontologia, da Faculdade de Odontologia do Centro Universitário Hermínio Ometto (Araras, São Paulo, Brasil). Os voluntários responderam a um questionário e foram submetidos a exame clínico e eletrovibratografia. Posteriormente, os voluntários foram classificados como portadores ou não portadores de desordem temporomandibular, considerando a presença de sensibilidade dolorosa na articulação temporomandibular e/ou presença de ruídos articulares. A prevalência dos fatores estudados foi calculada juntamente com a associação entre cada fator e a presença de desordem temporomandibular foi analisada pelo teste do qui-quadrado. Resultados: A prevalência de desordem temporomandibular na amostra avaliada foi de 42,9% e associação significante foi encontrada entre desordem temporomandibular e ruídos articulares (p<0,05); e entre desordem temporomandibular e bruxismo (p<0,05). Conclusão: Os resultados sugerem que pacientes com presença de bruxismo e ruídos articulares precisamente diagnosticados devem ser monitorados quanto ao aparecimento de sinais e sintomas de desordem temporomandibular.

Objective: To verify the prevalence of signs and symptoms of temporomandibular disorder and their association with joint noise, joint hypermobility, occlusal interference, orthodontic treatment and bruxism in a specific population composed of young university students. Methods: One hundred and seventeen (117) volunteers (mean age of 22 years) were selected from the undergraduate course in Dentistry at the School of Dentistry of the "Centro Universitário Hermínio Ometto" (Araras, São Paulo, Brazil). The volunteers answered a questionnaire and were submitted to clinical and electrovibratography exams. Afterwards, the volunteers were classified as either having temporomandibular disorder or not, considering the presence of painful sensitivity in the temporomandibular joint and/or presence of joint noise. The prevalence of the studied factors was calculated together with the association between each factor, and the presence of temporomandibular disorder was analyzed by the Chi-square test. Results: The prevalence of temporomandibular disorder in the evaluated sample was 42.9% and significant association was found between temporomandibular disorder and joint noise (p<0.05); and between temporomandibular disorder and bruxism (p<0.05). Conclusion: The results suggest that patients with presence of precisely diagnosed bruxism and joint noise should be monitored with regard to the appearance of signs and symptoms of temporomandibular disorder.

Fractographic analysis, accuracy of fit and impact strength of acrylic resin

This study evaluated accuracy of fit, impact strength, types and morphology of fractures of a microwave acrylic resin polymerized with a cycle alternative to that recommended by the manufacturer. Onda Cryl was polymerized according to the manufacturer's instructions (MC), 3 min at 360 W, 4-min pause, and 3 min at 810 W; and with an alternative cycle (AC) of 6 min at 630 W. Accuracy of fit was measured at 3 points at the right (A) and left (B) ridge crests and at the midline (C) on the posterior palatal seal for each denture base (n = 10/group). The measurements were taken immediately after finishing and after 30-day storage in water. The impact strength test (Charpy method) was performed with a 40 kJ/cm load (n = 20/group). Fractographic analysis was accomplished for all fragments and the fracture types were characterized by means of their morphology, crack propagation angles and microstructure. Accuracy of fit data were analyzed by ANOVA, impact strength and radius values were compared by the t test, and the fractographic analysis data, by the Wilcoxon Mann-Whitney test. The significance level was fixed at p < 0.05. No statistical differences were found between the two cycles of polymerization used. However, after the 30-day storage period in water, the denture bases showed better fit (P < .05). Most of the fractures were classified as brittle (MD: 70 percent, AC: 80 percent). Based on the results of this study, it could be concluded that both polymerization cycles are adequate to polymerize the denture resin studied.

Effect of dental wear, stabilization appliance and anterior tooth reconstruction on mandibular movements during speech

This study described changes in mandibular movements during pronunciation of /m/ and /s/ sounds in Portuguese, in patients presenting dental wear before and after appliance insertion and tooth reconstruction. Subjects were divided into a control group of dentate patients and an experimental group of patients with incisal tooth wear due to bruxism. A magnetic jaw tracking device measured the jaw opening, and translations to left and right sides of the mandible during pronunciation of phonemes. Evaluations were carried out 1 week and immediately before appliance insertion; 24 h, 7, 30 and 60 days after appliance insertion; and 1 week and 1 month after tooth reconstruction. Data were submitted to two-way ANOVA, Mann-Whitney and Friedman tests (p<0.05). Jaw opening was different (p<0.05) for both sounds in all periods. The anteroposterior amplitude for /s/ showed differences immediately before and 1 month after appliance insertion (p<0.05). Lateral amplitude for the right side showed differences between groups after appliance insertion for /s/, and 1 and 2 months after appliance insertion for the /m/ (p<0.05). Volunteers with anterior tooth wear had a wider opening movement, and the movements during speech of /m/ and /s/ sounds were not changed after appliance insertion and reconstruction of teeth.

O objetivo deste estudo foi verificar alterações nos movimentos mandibulares durante a pronúncia dos fonemas /m/ e /s/ da língua portuguesa, em pacientes com desgaste dental incisal antes a após a instalação de placas interoclusais e restauração dos dentes. Os voluntários foram divididos em grupo controle, composto por pacientes dentados, e grupo experimental composto por pacientes com desgastes incisais devido ao bruxismo. Desvios laterais para direita e esquerda, e de abertura foram mensurados por meio do método eletromagnético do registro do traçado mandibular durante a pronúncia dos fonemas /m/ e /s/. As avaliações foram realizadas 1 semana e imediatamente antes da instalação de placas interoclusais; 24 h, 7, 30 e 60 dias após a instalação das mesmas, e 1 semana e 1 mês após a restauração dos dentes. Os resultados foram submetidos à ANOVA a dois critérios e testes de Mann-Whitney e Friedman t (p<0,05). O movimento de abertura foi diferente (p<0,05) para ambos os sons em todos os períodos avaliados. Houve diferença (p<0,05) na amplitude anteroposterior durante pronúncia do som /s/ imediatamente antes e 1 mês após a instalação da placa. O desvio lateral para o lado direito apresentou diferença (p<0,05) entre grupos durante a pronúncia do /s/ em todos os períodos após a inserção da placa, e 1 mês e 2 meses após a inserção da mesma para o som /m/. Pacientes com desgaste dental anterior apresentaram amplo movimento de abertura, e movimentos mandibulares durante a pronúncia dos sons /m/ e /s/ não foram alterados após a instalação de placa e restauração dos dentes.

Implante imediato em local cronicamente infectado: avaliação após 12 meses / Immediate implant in infected site: evaluation after 12 months

Atualmente, o implante imediato após a extração de um elemento dentário com presença de lesão periapical crônica não é contra-indicado, desde que todas as medidas pré e pós-operatórias, bem como durante a cirurgia, sejam rigorosamente obedecidas. O presente relato de caso clínico tem a finalidade de descrever o protocolo realizado ao se optar pela implantação imediata após a remoção do foco de infecção simultaneamente à extração dentária. Exames clínicos e radiográficos foram realizados no dia da cirurgia do implante, 4 e 12 meses após. O acompanhamento após 12 meses revelou o sucesso do caso e principalmente, a necessidade da proservação contínua em casos onde a opção são tratamentos menos conservadores, sendo o tempo de 12 meses o período inicial deste acompanhamento.

Nowadays immediate dental implantation after chronic lesion removal is indicated when all care is carried out before, during and after surgery. The current relate describes the protocol carried out when immediate dental implantation is made after chronic lesion removal simultaneously to dental extraction. Clinic and radiographic exams were done in the surgery day and after 4 and 12 months. After 12 months of follow-up, the success of the procedure was confirmed. However, it was shown the needed of long-term follow-up when the choose treatment is less conservative. The 12 months is the initial follow-up.

Sistema ôattachmentõ bola mini para implantes angulados em sobredentaduras / Attachment ball system for angulated implants in overdentures

Novos protocolos para a reabilitação protética são resultados do constante avanço da implantodontia, resultando no alto índice de sucesso clínico das sobredentaduras ou overdentures. Entretanto, uma das limitações clínicas deste tipo de prótese apontada por alguns profissionais é o risco de não se obter um posicionamento ideal das fixações. Em virtude desta modalidade de tratamento se constituir na opção primária para reabilitação de pacientes desdentados totais com a finalidade de se controlar a reabsorção óssea fisiológica do rebordo residual em pacientes desdentados totais, este trabalho tem como objetivo apresentar um caso clínico com um novo sistema ôattachmentõ bola, que permite sua utilização em implantes retos e angulados.

Evaluation of surface characteristics of Ti-6Al-4V and Tilite alloys used for implant abutments

The aim of this study was to evaluate surface free energy (SFE), surface roughness (SR) and surface hardness (SH) of two commercially available materials for fabricating dental implant abutments. In addition, the specimens were investigated by scanning electron microscopy (SEM) to determine the surface morphology. Twenty five discs (5 x 2 mm) of Ti-6Al-4V and Tilite (Ni-Cr-Ti) alloys were used in this study. Surface free energy was determined by the contact angle formed between a drop of distilled, deionized water and the surface of the specimen of each material. The surface roughness was measured with a mechanical profilometer and the surface hardness was evaluated by means of the Vickers hardness micro indentation test. SFE, SR and SH data were analyzed using one-way ANOVA (p < 0.05). Statistical differences (p < 0.05) were found between Ti-6Al-4V (36.2 erg.cm-2; 0.2 æm) and Tilite (30.9 erg.cm-2; 0.16 æm) for SFE and SR. However, the differences between the surface hardness values of Ti-6Al-4V (325.0 kg/mm²) and Tilite (324.3 kg/mm²) were not statistically significant (p > 0.05). Evaluations by SEM revealed different surface morphology. Within the limits of this study, it can be concluded that the Ti-6Al-4V and Tilite alloys showed differences in surface properties, except for surface hardness, suggesting that both alloys may be considered appropriate for producing abutments. Further studies are, however, necessary to elucidate the biological responses to implant abutments made with these alloys.

O objetivo deste estudo foi avaliar a energia livre de superfície (ELS), rugosidade superficial (RS) e dureza de superfície (DS) de dois materiais disponíveis comercialmente para fabricação de "abutments" de implante. Em acréscimo, os espécimes foram investigados por microscopia eletrônica de varredura (MEV) para determinar a morfologia de superfície. Vinte e cinco discos de ligas de Ti-6Al-4V e Tilite (Ni-Cr-Ti) (5 x 2 mm) foram usados neste estudo. A energia livre de superfície foi determinada pela mensuração do ângulo de contato formado entre uma gota de água destilada e deionizada e a superfície do espécime para cada material. A rugosidade superficial foi mensurada com uso de um rugosímetro e a dureza de superfície foi avaliada por meio do teste de microdureza Vickers. Os dados foram analisados usando Análise de variância (P < 0,05). Foram encontradas diferenças significantes (P < 0,05) para os valores de ELS e RS entre Ti-6Al-4V (36,2 erg.cm-2; 0,2 æm) e Tilite (30,9 erg.cm-2; 0,16 æm). Entretanto, os valores de dureza de superfície não foram diferentes para ambos os materiais (Ti-6Al-4V - 325,0 kg/mm² e Tilite - 324,3 kg/mm²) (P > 0,05). A análise topográfica dos materiais pela MEV revelou superfícies diferentes. Dentro das limitações deste estudo, concluiu-se que as ligas de Ti-6Al-4V e Tilite mostraram diferenças nas propriedades de superfícies, exceto dureza, sugerindo que ambas as ligas são adequadas para a confecção de "abutments". Entretanto, estudos são necessários para evidenciar as respostas biológicas aos "abutments" de implantes confeccionados com essas ligas.